Field of the Invention
The present disclosure relates to a semiconductor device manufacturing method using dual damascene method, and a photoelectric conversion device.
Description of the Related Art
In Japanese Patent Application Laid-Open No. 2008-147588, a via-first dual damascene method is disclosed. In Japanese Patent Application Laid-Open No. 2008-147588, etching stoppers (104, 107) are disposed under a wiring interlayer film (103) and a via interlayer film (105).
In Japanese Patent Application Laid-Open No. 2010-087190, it is described that a dual damascene structure is configured in which a third plug (216) and a first wiring (217) are connected to a second plug (212). It is also described that a second opening (216h) in which the third plug (216) is disposed is formed in a second insulating film (214) first, and then a first opening (217h) in which the first wiring (217) is disposed is formed in a third insulating film (215).
In Japanese Patent Application Laid-Open No. 2008-147588, in order to form four types of insulators included in a wiring structure, it is necessary to perform film formation four times, which is disadvantageous in obtaining a low profile wiring structure. When it is attempted to reduce the thickness of the four types of insulators for achieving low profile, it may become difficult to perform uniform film formation of the respective insulators, or sufficient etching stopper function may not be obtained, resulting in a decrease in reliability.
When the second opening is formed first as in Japanese Patent Application Laid-Open No. 2010-087190, the earlier-exposed second plug is exposed to the etching for forming the first opening. As a result, the second plug may be damaged, the resistance of the second plug may be increased, or contamination may be caused due to metal included in the second plug. Thus, reliability may be decreased.
An object of the present disclosure is to provide a semiconductor device manufacturing method such that both low profile and reliability are achieved. Another object of the present disclosure is to increase the sensitivity of a photoelectric conversion device.